1. Field of the Invention
This invention pertains to agricultural equipment, and more particularly to apparatus useful in animal husbandry.
2. Description of the Prior Art
Handling large animals such as swine and cattle is a difficult and even dangerous job. The animals are far stronger than the persons trying to manage them, so mechanical aids are commonly employed to direct desired animal movements. Examples of large animal managing equipment include various squeeze chutes manufactured by For-Most, Inc. of Hawarden, Iowa, and by Palco, Inc. of Belle Plaine, Iowa.
A very important application of large animal management concerns dairy cows. For efficient milking, the cows must be calmly constrained at specific locations. Various equipment, such as stanchions, have been developed to constrain the cows in place, not only for milking but also for treating them for injury or illness.
In addition to the specific equipment that physically constrains cows at desired places for milking, the general milking environment has undergone continuous development over the years. Many dairy barns now include a pit parlor having stalls in which the cows stand at an elevation higher than that of the farmer. Headgates of various types are employed to firmly constrain the cows in the stalls while they are milked. The headgates are also useful for constraining the cows for medical or other treatment. The milking equipment is integrated into the parlors such that it remains in the same place during the entire milking operation. The idea is to move the cows to and from the milking equipment at the stalls and not move the milking equipment to and from the cows. Another advantage of pit parlors is that the farmer can work without bending and stooping to clean, milk, and treat his cows.
Although pit parlors greatly increase efficiency, they suffer the disadvantage of being very costly to install. Consequently, only relatively large operations can afford them. Moreover, the farmer must remain on his feet during the entire milking operation.
In an effort to obtain the benefits of pit parlors without their expense, flat barn parlors have recently been developed. In flat barn parlors, the farmer and the cows walk on the same barn surface, i.e., the barn floor. Accordingly, a new building or major changes to a barn floor or foundation are not required, which is a substantial cost benefit.
Some milking stalls of flat barn parlors are designed with headgates that open in only one direction. A headgate is operated to accept the head and neck of a cow and then closed and locked during milking or other procedures. For the cow to leave the stall, she must back up after the farmer has unlocked the headgate. That action is undesirable for several reasons. Some animals are reluctant to walk backwards, so they must be prodded to do so. Some cows tend not to walk straight back, so they often bump into the milking equipment. Consequently, the farmer must guide the cow backwards. Since the next cow cannot enter the stall until the previous cow is completely out of the way, congestion at the stall is inevitable. The time necessary for the farmer to clear a cow from the stall is wasted.
A better type of headgate is one that opens in two directions. The headgate opens to a ready position to accept the cow's head and neck, and the headgate locks at a closed position. When the farmer unlocks the headgate, the cow is able to walk forward, forcing the headgate open to an exit position. That design greatly improves cow traffic by eliminating the problems associated with backing a cow out of her stall.
However, prior walk-through headgates are not entirely satisfactory. They tend to remain open after the cows have passed through them, so the farmer must leave his milking station to close them. That activity represents non-productive time. In an attempt to make headgates self-closing, different types of spring and pneumatic mechanisms have been employed. The prior spring and pneumatic actuated headgates have not proven completely reliable. Further, the springs or pneumatic devices swing the headgates with undesirably high speeds such that they bang closed with a noisy shock. The farmer still must manually open a closed headgate to the ready position to accept the next cow. Finally, the springs exert uncomfortable forces on the cow's shoulders, sides, and pins as she pushes the headgate open and walks through it when leaving the stall.
Thus, a need exists for improvements in animal headgates.